Alternating-current heater.



PATENTBD DEC. 18, 1906.

J. P. MGELEOY.

ALTBRNATING CURRENT HEATER.

APPLICATION FILED SBPT G. 1906.

WITNESSES I INVENTOR M @Z @W W ATTY' UNITED STATES PATENT OFFICE.

JAMES F. MGELROY, OF ALBANY, NEW YORK, ASSIGNOR TO CONSOLI- DATED CAR HEATING COMPANY, OF ALBANY, NEW YORK, A COR- PORATION OF WEST VIRGINIA.

ALTERNATlNG-CURRENT HEATER.

Patented Dec. 18, 1906.

Application filed September 6, 1906. Serial No. 333,469.

To all whom it nuty concern.-

Be it known that I, J AMES F. MoELRoY, a citizen of the United States, residing at Albany, in the county of Albany and State of New York, have invented certain new and. useful Improvements in Alternating-Current Heaters, of which the following is a specification.

This invention relates to electric heaters for use on polyphase circuits; and it has for its objects, first, to provide a uniform heat distribution in a car or apartment together with proper balance and regulation of the alternating current consumed in the heater, and, secondly, to furnish a sectional heater system for polyphase currents, whereby one or more sections of the heater may be thrown into circuit either alternately or together and heating effects of different intensities obtained without disturbing the balance and regulation of the circuits. These objects are accomplished by the arrangement of circuits and heaters shown in the accompanying drawings, wherein Figure 1 represents a diagram showing one manner of arranging the circuits and switches in accordance with my invention. Fig. 2 represents a similar view showing a 1nodiiica tion.

The same reference characters indicate the same parts in the two views.

In Fig. 1 are shown two sections, each in cluding three wires 10 11 12 and 13 14 15 of a three-phase alternating circuit, these sections being designed for high heating and low heating, respectively, in order to give different intensities of heat within the car or other apartment containing the heaters. 16 16 are heater-coils connected with the high-heating circuit-wires 10 11 12 and grouped in three divisions, (designated by the respective numerals 17, 18, and 19,) there being four coils in each division arranged in parallel. (They might, however, be in se ries.) The coils of the respective divisions have their outer ends connected with the respective circuit-wires 10 11 12, division 17 being connected with wire 10, division 18 with wire 11, and division 19 with wire 12, and the inner ends of all the coils are connected by the common wire 20, giving the familiar star connection of three-phase wiring. Each division might of course have a greater or less number of coils than four, and the number of divisions will correspond with the number of phases in the circuit. 21. 21 represent the coils of the low-heating circuit, which are also grouped in three divisions of four coils each, whose outer ends are connected with the three wires 13 14 15 and their inner ends connected by a common wire 22. In practice the coil 16 and the coil 21 of any pair would preferably be mounted on the same porcelain core or support, and the arrangement portrayed is such as would be suitable for an electric-railway car with heaters under the seats.

The resistances and heating effects of the three divisions of coils in each section are made substantially equal, so that a uniform distribution of heat is secured throughout the car or apartment to be heated or that portion thereof occupied by the heaters, each division 17 18 19, for example, being of like heating capacity and resistance, and this also balances the entire three-phase section and prevents either part from being thrown out of phase and disturbing the balance and regulation of the circuit from which the heating-current is derivedas, for instance, the motor-circuit when the heaters are applied to a car. This equality of the three resistances is maintained for both the high-heating circuit 1O 11 12 and the low-heating circuit 13 14 15 by a proper construction and relation of the coils in each section and in the several divisions of each section. In addition the high-heating and low-heating coils of any division or pair and of the entire two heatingcircuits bear a certain predetermined relation in resistance and heating power. This relation is preferably two to one, the high-heating coils having twice the heating power of the lO\-l16lt1l1g coils. Thereby three degrees of heat may be secured by throwing in either one or both heating-sections. For this purpose Fig. 1 shows two three-pole switches 23 24 for opening and closing the connection between the line-wires and the two groups of wires 10 11 12 and 13 14 15, respectively. When only the switch 24 is closed, the low-heating coils 21 are made operative and the lowest degree of heat is secured. hen only the switch 23 is closed, the high-heating coils 16 are thrown in, giving the next higher degree of heat, and when IOC both switches are closed the highest degree of heat is obtained. It is one of the features of my invention that these diiferent amounts of heat, related in a predetermined ratio, may be obtained without throwing the multiphase system out of regulation.

Fig. 2 illustrates a modified arrangement in which the switches 23 24 are placed at the centers of the star circuitsnamely, at the places where the inner ends of the coils in each section converge-and when closed they serve to connect together the three inner wires 25 26 27 and 28 29 30 of the three-coil divisions composing each section. Either one or both sections may thus be thrown into circuit.

I claim 1. A balanced electric heater for multiphase circuits comprising heating-coils distributed within the apartment to be heated and located on the respective sides of the circuit, said coils being grouped in divisions of substantially equal resistance, so as to balance the circuit.

2. A heating system for multiphase circuits comprising a plurality of heating-coils grouped in divisions corresponding in number to the phases of the circuit, and so distributed as to heat the interior of an apartment at a plurality of points, said divisions being of substantially equal resistance and heating power, whereby the circuit is balanced and a uniform heating efiect secured.

3. An adjustable electric heater comprising a plurality of sections, each section composed of three divisions connected respectively on the three sides of a three-phase circuit, and switches for connecting one or more of the sections in circuit for varying the amount of heat, whereby the system is balanced with respect to the multiphase supplycircuit under all conditions of regulation.

4. An adjustable electric heater comprising a plurality of sections each of which includes a number of divisions corresponding with the number of phases in the multiphase circuit, and each division including one or more heating-coils, the coils of the respective sections being paired and related in heating power by a predetermined ratio, and the several divisions of each section being substantially equal in resistance and heating effect, together with means for throwing each division independently into and out of circuit. In testimony whereof I have hereunto set my hand,in the presence of two subscribing witnesses, the 4th day of September, 1906.

JAMES F. MGELROY.

Witnesses:

BEULAH CABLE, ERNEsT D. JANsEN. 

